This genus shows striking sexual dimorphism, the males with extensive
transparent areas across the forewing and at the costal angle of the hindwing,
the females resembling members of the Nygmiini, which has led to some confusionin the past. The venation generally resembles that of Leucoma and
Dendrophleps (See Leucoma Hübner), as do the male antennae and the reddening of
the forelegs (with the frons and abdominal tuft). M2 and M3 are connate in the
forewing and strongly stalked in the male hindwing (connate in the female); the
male hindwing is also modified to a rather squarish shape and M1 is lost. The
scaling is black in most species but can be brown or white, the type species
showing some variation in this.

The male genitalia show the same sort of asymmetry as seen in Leucoma
and Dendrophleps, with similar setae at the valve apices as in some
members of each genus. The abdominal sclerites are darkly sclerotised in the
male, more so than in Dendrophleps, and the pouches of the counter-tympanal
hoods associated with the first tergite are massive in the male.

The female has the base of the ductus rather convolute, thickened, and
the signum consists of a transverse flange arising from the centre of a small
rhomboidal plate of sclerotization. The ovipositor lobes are squarish.

Collenette (1949b) sorted out the basic synonymy within the genus when
describing two species from Bali. Unfortunately his findings were overlooked by
Schintlmeister (1994) who misidentified nuda and redescribed P. tamsi Collenette.
This investigation of the Bornean fauna has led to location of two taxa
described from females that had been misclassified in the Euproctis group.
The composition of the genus is reviewed briefly below.

Perina nuda Fabricius (= pura Walker, basalis Walker, combinata Walker,
subtincta Walker, ritsemae Heylaerts). This species extends from
the Indian Subregion to southern China but has not so far been recorded from
Sundaland. It is, as indicated by Collenette (1949b), clearly recognisable from
the strongly sinuous aedeagus, though males vary in the tone of their scaling,
from white through to black. The valves of the genitalia are slender, apically
bulbous rods. The locality for the type of subtincta Walker, a female in
U.M. Oxford, is given as E. Indies, which could mean India or Sundaland. The
facies resembles that of Indian material, lacking the extensive dark basal area
of the hindwing seen in Sundanian species. The concept of nuda in
Schintlmeister (1994) is incorrect (see below).

Perina sp. (slide 2483). This is an undescribed species from Sri Lanka. The
aedeagus resembles that of the Ilema subgenus Cadrusia species in
shape. The valves are slender, rod-like, longer and more robust than in nuda.

Perina lodra Moore comb. n. (= tamsi Collenette syn. n. and naessigi
Schintlmeister syn. n.). Differences from the more widely distributed
Sundanian species are described in the specific account below. The male
genitalia of naessigi, illustrated in the original description, match
those of tamsi. The distribution therefore ranges through Bali, Java and
Sumatra: the occurrence in India mentioned by Schintlmeister needs confirmation
on genitalic evidence, rather than that of facies. The synonymy of both
male-based taxa with lodra, based on a female, needs confirmation from
rearing a series of both sexes from a single female. Toxopeus (1948), in
describing Bradytera, voiced misgivings about the Toxoproctis males
with which other authors had associated it, and noted that the Javan series he
examined had been reared from Ficus religiosa, another pointer to its
identity as a Perina (See Perina sunda
sp.n). The venation and generalfacies are consistent with these features in nuda females. The
female of the Bornean species is as illustrated here. That of lodra has a
darker, more uniform brown forewing and a less extensive dark zone at the base
of the hindwing, extending to only just beyond half way.

Perina kalisi Collenette. This is only known from the holotype male from Bali and has
white scaling, rather than black, on the wings. In the male genitalia the valves
are short, broad, irregularly bilobed, the right much larger than the left.

Perina psamma Collenette comb. n. Collenette (1949b) mentioned a single male
of a further species from Sulawesi. The genitalia (slide 2484) resemble those of
nuda more than those of any Sundanian species, though the aedeagus is
straight rather than sinuous, albeit as robust as that of nuda. The
valves and uncus are similar, though the asymmetry of the uncus is less marked.
The taxon psamma from Sulawesi is based on females and was described in Euproctis.
Its venation and general facies show it to be a Perina, so it is
probably associated with the single male.

The larva of the type species was illustrated by Wang (1993), and
described by Sevastopulo (1938) and T.R.D. Bell (MS). Wang also illustrated the
pupa. The larva has a grey head and flanks, with the dorsum broadly black.
Within this black band there is a narrow wedge of grey over the thoracic
segments that tapers towards the head and then expands as a ‘T’ along the
anterior margin of the prothorax. The black over the abdominal segments is
circular on each and is bisected over the central three by a double pale yellow
band. The setae are white, arising from red verrucae. Segments A1 and A2 have
dorsal brush tufts on slight humps.

The larvae eat mature leaves, rest on the undersides of leaves and
wander about the tree a lot.

The pupa is bristly, piebald in dark grey and cream, the grey areas
being dorsal. The bristly setae are orange (pupa in Barlow colln). It is
suspended by its cremaster in a flimsy silken net on a curled, dead or dying
leaf of the host-plant.